Multi-catheter flexible robotic system

ABSTRACT

A multicatheter subsystem is provided for a steerable catheter robotic system. The subsystem includes a flexible output sheath, a plurality of flexible multi-lumen assemblies and a plurality of robotic instruments for performing a surgical procedure. The plurality of flexible multi-lumen assemblies extends through the outer sheath. Each of the multi-lumen assemblies has a proximal end and a distal end. Each of the robotic instruments is operatively and removably attachable to the distal end of one of the multi-lumen assemblies such that each instrument is teleoperable independently of every other robotic instrument. At least a first of the robotic instruments includes a plurality of interconnected articulating segments. Each of the articulating segments is operatively and removably attachable to a different one of the multi-lumen assemblies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of PCT/US2018/036349, filed Jun. 6,2018 which claims benefit of priority of U.S. Provisional PatentApplication Ser. No. 62/515,762, filed Jun. 6, 2017, entitled“MULTI-CATHETER FLEXIBLE ROBOTIC SYSTEM”, owned by the assignee of thepresent application and herein incorporated by reference in theirentiretiesy.

BACKGROUND

Remotely-controlled surgical instruments, which can include teleoperatedsurgical instruments (e.g., surgical instruments operated at least inpart with computer assistance, such as instruments operated with robotictechnology) as well as manually operated (e.g., laparoscopic,thorascopic) surgical instruments, are often used in minimally invasivemedical procedures. During such procedures, a surgical instrument, whichmay extend through a cannula inserted into a patient's body, can beremotely manipulated to perform a procedure at a surgical site. Forexample, in a teleoperated surgical system, cannulas and surgicalinstruments can be mounted at manipulator arms of a patient side cartand be remotely manipulated via teleoperation at a surgeon console.

In the present landscape of surgical robotics, the field of continuum(or flexible) surgical robotic systems is still very much indevelopment. These biomimetic systems, many modeled after tentacles ortrunks, allow for minimally-invasive access to previously unreachableanatomy. By developing these devices with a smaller footprint and morerobust laminate manufacturing techniques, lower impact surgery can beportably and efficiently performed in even tighter spaces thantraditional rigid surgical robots.

SUMMARY

In accordance with one aspect of the present disclosure, a multicathetersubsystem is provided for a steerable catheter robotic system. Thesubsystem includes a flexible output sheath, a plurality of flexiblemulti-lumen assemblies and a plurality of robotic instruments forperforming a surgical procedure. The plurality of flexible multi-lumenassemblies extends through the outer sheath. Each of the multi-lumenassemblies has a proximal end and a distal end. Each of the roboticinstruments is operatively and removably attachable to the distal end ofone of the multi-lumen assemblies such that each instrument isteleoperable independently of every other robotic instrument. At least afirst of the robotic instruments includes a plurality of interconnectedarticulating segments. Each of the articulating segments is operativelyand removably attachable to a different one of the multi-lumenassemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 show perspective views of a multi-catheter subsystem.

FIG. 3 shows one example of a multi-lumen assembly that is used to steera single one of the robotic instruments shown in FIGS. 1 and 2.

FIG. 4 shows a motor control assembly.

FIG. 5 shows a pully housing assembly.

FIG. 6 shows an example of a steerable catheter robotic system thatincludes the multi-catheter subsystem shown in FIGS. 1 and 2.

DETAILED DESCRIPTION

As described in more detail below, a steerable catheter robotic systemwith a significantly reduced size-footprint is provided for deploymentin field or outpatient pulmonary surgical procedures. The small size andportability of this system can help overcome a major disadvantage ofcurrent surgical robots which take up an immense amount of space inalready crowded-operating rooms, while still being able to imitate, copyand improve human capabilities. In some embodiments the dimensions ofthe robotic instruments or tools may be as small as 1 mm.

FIGS. 1 and 2 show perspective views of a multi-catheter subsystem 100that includes a flexible outer guide shaft 110 having a distal end fromwhich one or more robotic instruments extend. Although the embodimentshown in FIGS. 1 and 2 shows three robotic instruments 120 ₁, 120 ₂ and120 ₃ (“120”), more generally any number of such robotic instruments 120may be employed. In this particular embodiment the robotic instruments120 include a camera 120 ₁ and first and second grasping forceps 120 ₂and 120 ₃. A control assembly (not shown in FIGS. 1 and 2) is located atthe proximal end of the outer sheath 110 controls the operation of therobotic instruments 120.

In some embodiments each robotic instrument 120 may include two or morearticulating segments that provide the instrument with multiple degreesof freedom. For instance, as best seen in FIG. 2, the first graspingforcep 120 ₂ includes three articulating segments 125 ₁, 125 ₂ and 125₃. The second grasping forcep 120 ₃ may be similarly configured. Byemploying a suitable number of articulating segments, some instrumentsmay be supplied with 7 degrees of freedom of articulation (i.e.positional control of x, y, z in cartesian space, and roll-pitch-yaw inorientation, and an actuation degree of freedom such as a pinch grip ofa forcep), thereby essentially recovering the dexterity of a human hand.In such an embodiment a one-to-one mappings can be advantageouslyrealized of a teleoperating using to the robotic instrument. If morethan 7 degrees of freedom are provided to a given instrument, theinstrument can have additional degrees of freedom to conform to theenvironment without affecting the controllability of the 7 degrees offreedom that are controlled by the human operator. Some instruments mayhave additional elbow deflection locations that allow the shape of theinstrument to better conform to the environment.

When one of the robotic instruments is a camera, it may be operated withonly 6 degrees of freedom for full visual control, although the focaldepth (if so integrated) may be considered a 7^(th) degree of freedom.

FIG. 3 shows one example of a multi-lumen assembly 200 that is used tosteer a single instrument 120. Each of the lumens is formed from aflexible material such as a flexible polymer. The multi-lumen assembly200 extends through the outer guide shaft 110 shown in FIG. 1. Themulti-lumen assembly 200 includes a center channel 210 that has a liner212 that serves as an instrument port for one segment of a multi-segmentinstrument (or a complete instrument of a single-segment instrument).Surrounding the center channel 210 are a series of control lumens 220through which articulation wires (not shown) extend. In this example 4control lumens 220 ₁, 220 ₂, 220 ₃ and 220 ₄ are shown. The controllumens 220 are secured (e.g., fused) to the center channel 210.Articulation of the instrument segment located in the center channel 210is determined by the coordinated operation of the articulation wires viathe control assembly, which will be described below. The center channel210 and the control lumens 220 may extend through a flexible sheath 230(which itself extends through the outer guide shaft 110 shown in FIGS. 1and 2).

Each articulating segment of a multi-segment instrument includes its owndedicated multi-lumen assembly 200 for controlling that segment. Thedifferent multi-lumen assemblies 200 of a single multi-segmentinstrument may be concentrically arranged with one another.

As mentioned above, the multi-lumen assembly 200 may be fabricated fromflexible polymers. For example, in some embodiments the flexible sheath230 and center channel 210 may be formed from a varying durometerthermoplastic polymer such as a polyester block amide (available, forinstance, under the tradename PEBAX®). An optional stainless steel orfiber braid (not shown) may surround the flexible sheath 230. Likewise,in some embodiments the control lumens may be formed polymide and theliner 212 lining the center channel 210 may be formed from PTFE (i.e.,Teflon®). The use of flexible polymers for the multi-lumen assemblyaffords significant flexibility in short segments without deteriorationof the assembly and tight radiuses of curvatures can be achieved.Lamination of these polymers, which can become micron-thickness layers,enables these robotically controlled lumens to reach as small as 1 mm indiameter.

FIG. 4 shows a motor control assembly 400 that can be used inconjunction with a pully housing assembly 500 (FIG. 5) to control thefour pull wires that extend through the control lumens 220. The motorcontrol assembly 400 includes four motors 410 ₁, 410 ₂, 410 ₃ and 410 ₄(where motor 410 ₄ is not visible in FIG. 4). that each respectivelycontrol the rotation of a rotatable shaft 415 ₁, 415 ₂, 415 ₃ and 415 ₄.The pully housing assembly 500 includes four torque-limiting pulleys 510₁, 510 ₂, 510 ₃ and 510 ₄. When the pulley housing assembly 500 is matedwith the motor control assembly 400 each pulley 510 ₁, 510 ₂, 510 ₃ and510 ₄ is axially mounted on one of the shafts 415 ₁, 415 ₂, 415 ₃ and415 ₄. The pulley housing assembly 500 also includes a shaft mount 520onto which is mounted the outer guide shaft 110 and the multi-lumenassemblies 200 extending therethrough. Once installed, rotationalactuation of the motors 410 located in the motor control assembly 420 istranslated to linear actuation, providing four degrees of freedom toeach instrument segment.

The motor control assembly 400 includes an additional motor 4105 that isused to extend and retract the robotic instrument under its control.

The control of the robotic instruments is accomplished using inversekinematics to map Cartesian coordinates into the positions of the fourpull wires. Coordinates are first multiplied by a dynamically adjustablerotation matrix, and then by constants derived during a simplecalibration process in order to standardize actuation across multipleinstruments. A position-based control approach using analog values toscale targets in Cartesian space that are then mapped to R⁴, resultingin high position accuracy along with precise control over actuationvelocity. The final result is accurate and intuitive control over twodegrees of freedom per instrument, all mapped to a user interface.

FIG. 6 shows an example of the steerable catheter robotic system thatincludes the multi-catheter subsystem 110 shown in FIGS. 1 and 2, whichincludes the three instruments 120 ₁, 120 ₂ and 120 ₃. Like referencenumerals shown in FIG. 6 and the remaining figures denote like elements.As shown, the proximal end of the multi-catheter subsystem 110 includescontrollers 550 ₁, 550 ₂, 550 ₃ and 550 ₄ (“550”). Each controller 550includes one of the motor control assemblies 400 mated with one of thepulley housing assemblies 500. Controller 550 ₁ is used to controlinstrument 120 ₁, controller 550 ₂ is used to control instrument 120 ₂and controller 550 ₃ is used to control instrument 120 ₃. The additionalcontroller 550 ₄ is used control the overall movement of themulti-catheter subsystem 110.

Control of the steerable catheter robotic system via a user interface(not shown) focuses on two distinct tasks: robot movement and multiplecatheter articulation. Both movements can be controlled from a singleconsole. For instance, in one embodiment the operator is able to advancethe robot via a haptic joystick. The path of the multi-cathetersubsystem can be visualized on a display of the user interface console.The display may include a high-definition or 3-D screen. Additionalscreens within the console may allow for projection of imaging studiesor electromagnetic instrument registration for use during the procedurebeing performed. The joystick allows forward and backward movement and180° movement in an x and y plane of the distal tip. To preventtraumatic navigation, haptic feedback may be provided which isassociated with the platform movement. Once positioned in the desiredlocation, the platform can be fixed to allow stability during instrumentinsertion and movement.

As discussed above, in one embodiment there are two articulatinginstruments that can be inserted through the length of themulti-catheter subsystem. Movement of each instrument is controlled byindependent finger grasping interfaces. The instruments can be advancedor withdrawn by depression or retraction of a grasping unit. Ininstances where there are no grasping movements, the instruments may bemoved as if grasping a virtual pencil.

A wide variety of different interchangeable robotic instruments may beused in the multi-catheter subsystem. Examples of such instrumentsinclude, without limitation, biopsy cups, grasping forceps, injectionneedles, biopsy needles, laser introducers, basket retrievers, hotknives, clip appliers, and scissors. The instrument or instruments thatare used will be application-dependent. Examples of such applicationsinclude laryngeal, pharyngeal, hypopharyngeal, tracheal, bronchial,esophageal, stomach, large and small bowel applications. Additionally,applications include newer advanced endoscopic procedures, includingendoluminal tumor ablation in varying anatomic locations, PeroralEndoscopic Myotomy (POEM), and Natural Orifice Transluminal EndoscopicSurgery (NOTES).

Robotic instruments may be interchangeable so that the multi-cathetersubsystem 100 can swap the types and locations of instruments asrequired to generate different configurations for a user to extend theirability to work with tissues in a narrow space, extend their reach,improve their visual range, or improve the ergonomics of control. Thesoftware controlling the multi-catheter sub-system may reposition itscoordinate frame to match an intuitive viewpoint of the teleoperator.

In some cases it is possible that the system can introduce more roboticinstruments than a single user can control. In this scenario, both aprimary user and an assistant may operate different instruments throughthe same system, enabling multiple robotic instruments to be controlledsimultaneously. This encourages shared tasks, allowing assistants tohelp with the retraction of objects or environmental roadblocks whilethe primary user is operating on the exposed area.

One embodiment of the system may involve the autonomous control of oneinstrument that follows or performs some assistive task that follows thebehavior of a primary user. For example, a continuous ablation using alaser that reaches deeper within a site may be realized by having one ofthe robotic instruments follow a user-controlled ablation probe as itmoves through the environment, i.e., a robotically controlled camera. Inthis case one instrument would be teleoperated while the other isautonomous and following the teleoperated camera.

The ability to simultaneously control and steer multiple roboticinstruments can provide critical capabilities in manipulating areas oftissues with bimanual manipulation. For example, controlled stretchingof tissue or peeling of tissue can be achieved only with two or moreinstruments. Likewise, the ability to mount and control a cameraindependently of the other instruments (and vice-versa) is a significantadvantage over current endoscopic approaches where the endoscope is thecamera and dictates the controllability of the instruments exiting fromits orientation-fixed instrument lumen. Moreover, the multi-cathetersystem may be mixed with manual instrumentation given that theinstrumentation fits within the available lumens for control.

Another advantage of the steerable catheter robotic system describedherein is that one of its intracorporeal instruments can be used tostabilize another when there is a desire for improved stiffness. Forexample, an outstretched robotic instrument may become too compliant tolift a tissue that is far away. A support provided from a second roboticinstrument may be devised to generate mechanical leverage that canamplify the force generation or the reachability of the original,unsupported instrument. In the same way, the robotic instruments may beused to support the sub-system in general and create anchors to providestabilization against patient or anatomical motions or more generally tocombat moment-arm effects.

Yet another advantage of the steerable catheter robotic system describedherein arises in those embodiments that are fabricated exclusively frompolymer or other non-metallic materials since these embodiments may beused in conjunction with magnetic resonance imaging (MRI) techniques.

Reference in the specification to “an embodiment,” “one embodiment,”“some embodiments,” or “other embodiments” means that a particularfeature, structure, or characteristic described in connection with theembodiments is included in at least some embodiments, but notnecessarily all embodiments. The various appearances of “an embodiment,”“one embodiment,” or “some embodiments” are not necessarily allreferring to the same embodiments. If the specification states acomponent, feature, structure, or characteristic “may”, “might”, or“could” be included, that particular component, feature, structure, orcharacteristic is not required to be included. If the specification orclaim refers to “a” or “an” element, that does not mean there is onlyone of the element. If the specification or claims refer to “anadditional” element, that does not preclude there being more than one ofthe additional element.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative of and not restrictive on the broad invention, andthat this invention not be limited to the specific constructions andarrangements shown and described, since various other modifications mayoccur to those ordinarily skilled in the art.

1. A multicatheter subsystem for a steerable catheter robotic system,comprising: a flexible output sheath having a proximal end and a distalend; a plurality of flexible multi-lumen assemblies extending throughthe outer sheath, each of the multi-lumen assemblies having a proximalend and a distal end; a plurality of robotic instruments for performinga surgical procedure, each of the robotic instruments being operativelyand removably attachable to the distal end of one of the multi-lumenassemblies such that each instrument is teleoperable independently ofevery other robotic instrument, at least a first of the roboticinstruments including a plurality of interconnected articulatingsegments, each of the articulating segments being operatively andremovably attachable to a different one of the multi-lumen assemblies.2. The multicatheter system of claim 1 wherein the first instrument isconfigured to have 7 degrees of freedom.
 3. The multicatheter system ofclaim 1 wherein the flexible outer sheath, the plurality of flexiblemulti-lumen assemblies and the plurality of robotic instruments areformed from polymer materials.
 4. The multicatheter system of claim 1wherein each of the multi-lumen assemblies includes at least oneactuating arrangement for steering the instrument attached thereto. 5.The multicatheter system of claim 4 further comprising a controlassembly operatively coupled to the proximal lend of the multi-lumenassemblies for providing rotational movement that imparts translationalmovement to the actuating arrangement.
 6. The multicatheter system ofclaim 5 wherein at least one of the actuating arrangements includes: aplurality of control lumens attached to and surrounding a central lumento which one of the instruments is removably attached; and a pluralityof pull wires each extending through one of the control lumens, aproximal end of each of the pull wires being operatively connected tothe control assembly.